Supplement to Journal of Nematology 23(4S):620-623. 1991. © The Society of Nematologists 1991. Associated with Blackberry in Arkansas

E.J. WEHUNT, 1 A. M. GOLDEN, ~ J. R. CLARK, 3 T. L. KIRKPATRICK,4 E. C. BAKER, 9 AND M. A. BROWN 1

Abstract: A survey of the nematodes in blackberry (Rubus sp.) rhizospheres was conducted in Arkansas from 1986 to 1989. The state was divided arbitrarily into four quadrants. A total of 134 soil samples was collected, and 150-cm 3 subsamples were assayed for nematodes. Twenty-one species of plant-parasitic nematodes in 11 genera were extracted from the samples. There were differences (P = 0.05) among quadrants of the state in percentage occurrence of the nematodes and in population densities in samples. Xiphinema americanum, Helicotylenchus spp. (H. paraplatyurus, H. platyurus, and H. pseudorobustus), and Pratylenchus spp. (P. vulnus and P. zeae) were found in all quadrants. Xiphinema americanum population density was near 1,000 per 150 cm 3 soil in soil samples from two locations. Other nematodes found in one or more quadrants were Criconemella spp. (C. axeste, C. curvata, C. denoudeni, C. ornata, C. sphaerocephala, and C. xenoplax), minor, Tylenchorhynchus clay- toni, Hirschmanniella oryzae, Hoplolaimus magnistylus, Scutellonema bradys, and undescribed species of Criconema, Tylenchulus, Xiphinema, and Meloidogyne. CriconemeUa sphaerocephala and Helicotylenchus plat),urus are reported from Arkansas for the first time. Helicotylenchus paraplatyurus is reported from the United States for the first time. Key words: blackberry, CriconemeUa sphaerocephala, Helicotygenchus paraplatyurus, Helicotylenchus pla- tyurus, , Rubus spp., survey, Xiphinema americanum.

Interest is increasing in blackberries (Ru- raslSberries (Rubus sp.) by M. hapla Chit- bus spp.) as an alternative crop for small wood enhances the development of crown family farms in Arkansas. Goodey et at. gall caused by Agrobacterium tumefaciens (8). (7) list associations of several nematode Root-lesion nematodes, Pratylenchus spp., genera with Rubus spp., including Aph- have been associated with poor perfor- elenchoides, Criconema, Criconemoides, Para- mance of Rubus spp. in British Columbia tylenchus, Pratylenchus, Meloidogyne, and (1), North Carolina (4,5), Maryland (6), and Xiphinema. New Jersey (9). Application of control mea- Pratylencyhus spp., Xiphinema spp., and sures in areas infested with Pratylenchus Paratylenchus spp. often occur in raspberry penetrans (Cobb) Filipjev and Schuurmans and blackberry plantings in the United Stekhoven and Xiphinema bakeri Williams States, and Meloidogyne spp., Hdicotylenchus increased growth and yield of red rasp- spp., and CriconemelIa spp. are occasionally berries (12). Red raspberries differed in re- found; however, pathological information action to P. penetrans, possibly indicating a is lacking (15). source of resistance (16). Xiphinema amer- The root-knot nematodes Meloidogyne icanum Cobb transmits ringspot vi- spp. have been reported on brambles (Ru- rus of raspberries in British Columbia (13) bus spp.) in the United States (8,14), Africa and probably reduces growth by its feeding (11), and Australia (2). Infestation of red activities. Nematodes cause approximately a 2% loss by direct damage to blackberry pro- Received for publication 28 July 1990. duction in the United States (3). As black- Published with the approval of the Director, University of berry production increases, economic losses Arkansas Agricultural Experiment Station. Research Plant Pathologist (Nematologist) and Supervi- to nematodes and associated viruses prob- sory Research Scientist, USDA ARS, South Central ably will increase. Family Farm Research Center, Booneville, AR 72927-9214. 2 Zoologist, USDA ARS, Nematology Laboratory, Belts- In Arkansas information is lacking on ville, MD 20705. nematodes present, the potential damage, Resident Director, University of Arkansas, Fruit Substa- tion, Clarksville, AR. and methods of damage management. This 4 Associate Professor, University of Arkansas, Southwest survey was conducted to identify nema- Research and Extension Center, Hope, AR 71801. Resident Director, University of Arkansas, Strawberry todes associated with blackberry in Arkan- Substation, Bald Knob, AR 72010. sas. 620 Nematodes on Blackberry: Wehunt et al. 621

MATERIALS AND METHODS Arkansas was divided arbitrarily into quadrants--northwest (NW), northeast (NE), southeast (SE), and southwest (SW; Fig. 1). Soil samples were collected in the quadrants from "wild" and cultivated blackberry, regardless of type or history of cultivation, soil type, or previous produc- tion practices. Soil was sampled with a 2.5- cm-d soil tube 20 cm deep. A sample con- sisted of 4-10 cores. A total of 134 samples was taken from the SW, SE, and NE quad- rants from July to October 1989 and from the NW quadrant at various times from 1986 to 1989. Samples were brought to the laboratory in sealed polyethylene bags, FIG. 1. Locationof quadrants and counties (O) in thoroughly mixed, and a 150-cm s subsam- Arkansas from which samples were collected from ple was processed by the sugar-flotation- blackberry soil. centrifugation method to extract nema- todes (10). rant, but numbers per sample were lower Nematodes were examined, identified to (P - 0.05) in the SE quadrant. genus, and counted with the aid of a dis- Xiphinema spp. (X. americanum and an un- secting microscope with magnifications to described species) were found in all quad- 140 x. Hand-picked specimens were killed rants. The percentage occurrence of these with heat, preserved in 3% formaldehyde species was higher (P = 0.05) in the NE solution, and identified to species with the quadrant, and population densities were aid of a compound microscope with mag- higher (P = 0.05) in the SW and NE quad- nifications to 1,250 x. Specimens submit- rants. In samples containing Xiphinema spp., ted for identification to species are in the numbers ranged from 62-454/150 cm 3 USDA Nematode Collection, Beltsville, soil. In noncultivated plantings, Xiphinema spp. numbers were 4-467/150 cm 3 soil. In MD., USA. Data were analyzed by methods of least squares. two cultivated plantings, one each in the SW and NE quadrants, X. americanum num- bers were near 1,000/150 cm 3 soil. In Lo- RESULTS AND DISCUSSION gan County (NW quadrant), samples from Twenty-one species of plant-parasitic "wild" blackberry plantings contained high nematodes were found in the 134 samples numbers of X. americanum, whereas sam- of blackberries. Members of three genera ples from outside the "patches" contained were found in all quadrants; four genera low numbers. These results suggest para- were found in three quadrants; and four sitism of blackberry by the nematode. genera were found in one quadrant (Table Pratylenchus spp. (P. vulnus Allen & Jen- 1). sen and P. zeae Graham) occurred in all Helicotylenchus spp. (H. paraplatyurus, quadrants in over 25% of the samples, with Siddiqi; H. platyurus Perry, Darling & mean numbers ranging from 7-46/150 Thorne; P. pseudorobustus (Steiner) Gold- cm a soil. The percentage occurrence and en; and an undescribed species) were found numbers per sample were not different (P in 85% of the samples with mean popula- = 0.05) among quadrants. tion densities of 140/150 cm 3 soil. Helico- Criconemella spp. (C. axeste (Fassuliotis & tylenchus spp. were found in all quadrants. Williamson) Ltrc & Raski, C. curvata (Raski) Percentage occurrence of Helicotylenchus Luc & Raski, C. denoudeni (DeGrisse) Luc spp. was lower (P = 0.05) in the SW quad- & Raski, C. ornata (Raski) Luc & Raski, C. 622 Supplement to Journal of Nematology, Volume 23, October 1991

TABLE 1. Nematode genera found in soil around roots of blackberries (Rubus spp.) in four quadrants of Arkansas.

Quadrant Genus Occurrencet NW SW NE SE

Helicotylenchus % 91 a 72 b 100 a 91 No. 177 a 195 a 157 a 13 Pratylenchus % 17 a 28 a 29 a 42 No. 16 a 23 a 28 a 9 Xiphinema % 86 b 66 b 100 a 75 No. 122 b 331 a 230 a 64 Paratylenchus % 49 a 8 b 0 8 No. 91 a 18 a 0 5 Tylencorhynchus % 19 b 42 a 0 17 No. 39 a 22 a 0 8 Circonemella % 24 b 56 a 0 17 No. 80 a 142 a 0 5 Paratrichodorus % 5 b 66 a 0 83 No. 33 a 61 a 0 17 HirschmannieUa % 2 0 0 0 No. 1 0 0 0 Tylenchulus % 2 0 0 0 No. 1 0 0 0 Hoplolaimus % 3 0 0 0 No. 2 0 0 0 Meloidogyne % 0 28 0 0 No. 0 59 0 0

Means in the same row followed by common letters do not differ significantly (P = 0.05). t % = proportion of samples containing the nematode genus. No. = average number of nematodes/150 cm 3 soil in samples containing the nematode genus. sphaerocephala (Taylor) Luc & Raski, and other quadrants. Differences in population C. xenoplax (Raski) Luc & Raski) were found densities among quadrants were not sig- in 33% of the total samples, with average nificant. Paratylenchus spp. were found in numbers of 38/150 cm ~ soil. Percentage 49% of the samples in the NW quadrant, infestation was higher (P -- 0.05) in the SW with mean numbers of 91/150 cm 3 soil. quadrant than in the NW and SE quad- Criconema sp., HirschmannieUa oryzae (Von rants. Differences in population densities Breda de Hann) Luc & Goodey, Hoplolai- were not significant: mus magnistylus Robbins, Scutellonema bra- Paratrichodorus minor (Colbran) Siddiqi dys (Steiner & LeHew) Andrassy, and a Ty- was found in samples from three quad- lenchulus sp. were found in the NW rants. Percentage occurrence was higher quadrant in low numbers and in a few sam- (P = 0.05) in the SE and SW quadrants than ples. in the NW quadrant. Population densities In addition to the undescribed Meloido- were low, and differences among quad- gyne sp. and Xiphinema sp. recorded here, rants were not significant (P = 0.05). new records are established for Cricone- Juveniles of an undescribed Meloidogyne mella sphaeroeephala and Helicotylenchus sp. were found in 28% of the samples from platyurus in Arkansas, and a record is es- the SW quadrant, with populations of 59/ tablished for Helicotylenchus paraplatyurus 150 cm 3 soil. Blackberry may not be a host in the United States. of this nematode. The percentage occur- Fewer genera of nematodes were found rence of Tylenchorhynchus claytoni Steiner in the NE quadrant than in other quad- was higher (P = 0.05) in the SW than in rants. Of the nematodes found in all quad- Nematodes on Blackberry: Wehunt et al. 623 rants, Helicotylenchus spp., Pratylenchus spp., 4. Goheen, A. C. 1954. Meadow nematodes on and Xiphinema sp. were found in lower (P raspberries and blackberries. Plant Disease Reporter 39:906-908. = 0.05) numbers in the SE quadrant than 5. Goheen, A. C., and C. F. Williams. 1955. Sea- in the other quadrants in which they oc- son fluctuations in the population of meadow nema- curred. Paratrichodorus minor occurred in todes in the roots of cultivated brambles in North the SW and SE quadrants in moderate Carolina. Plant Disease Reporter 39:904-905. 6. Golden, A. M., and R. Converse. 1965. Nema- numbers, but this nematode was almost ab- todes on raspberry in the Eastern United States. Plant sent from the northern quadrants. Disease Reporter 49:987-991. Xiphinema spp. (principally X. american- 7. Goodey, J. B., M. T. Franklin, and D.J. Hooper. urn), Helicotylenchus spp., and Pratylenchus 1965. T. Goodey's The nematode parasites of plants catalogued under their hosts. Farnham Royal, En- spp. were found in both cultivated and gland: Commonwealth Agricultural Bureaux. "wild" plantings of blackberry in all quad- 8. Griffin, G. D., J. L. Anderson, and E. C. Jor- rants. Based on our results and on pub- genson. 1968. Interaction of Meloidogyne hapla and Agrobacterium tumefaciens in relation to raspberry cul- lished information, the nematode most tivars. Plant Disease Reporter 52:492-493. likely to affect production of blackberries 9. Hutchinson, M. T., J. P. Reed, H. T. Streu, A. in Arkansas is X. americanum. Nematode A. DiEdwardo, and P. H. Schroeder. 1961. Plant control measures in bramble plantings in- parasitic nematodes of New Jersey. New Jersey Ag- ricultural Experiment Station Bulletin 796:1-33. fested with X. americanum exhibited in- 10. Jenkins, W. R. 1964. A rapid centrifugal-flo- creased growth and yield (13). This nema- tation technique for separating nematodes from soil. tode is also a vector of a virus disease of Plant Disease Reporter 48:692. brambles (13) and of several viruses of oth- 11. Martin, G. C. 1959. Plants attacked by root- knot nematodes (Meloidogyne spp.) in the Federation er plants. of Rhodesia and Nyasaland. Nematologica 4:122-125. Pratylenchus penetrans, a pathogen of 12. McElroy, F. D. 1975. Nematode control in brambles, was not found in this survey, al- established raspberry plantings. Pp. 445-446 in F. though it occurs in Arkansas. of Lamberti, C. E. Taylor, and J. W. Seinhorst, eds. Nematode vectors of plant viruses. London: Life Sci- brambles by the two Pratylenchus spp. found ence. in this survey has not been reported. 13. McElroy, F. D. 1977. Effect of two nematode species on establishment and yield of raspberries. Plant LITERATURE CITED Disease Reporter 61:277-279. 14. Neal, N. C. 1889. The root-knot disease of 1. Bosher, J. E. 1954. Root-lesion nematodes as- the peach, orange and other plants in Florida due to sociated with root decline of small fruits and other the work of Anguillula. Bulletin 20, USDA Bureau of crops in British Columbia. Canadian Journal of Ag- Entomology, Washington, DC. ricultural Science 34:429-431. 15. United States Department of Agriculture. 2. Colbran, R. C. 1958. Studies of plant and soil 1978. Controlling diseases of raspberries and black- nematodes. 2. Queensland host records of root-knot berries. Farmers' Bulletin No. 2208, USDA, Wash- nematodes (Meloidogyne species). Queensland Journal ington, DC. of Agricultural Science 15:101-136. 16. Vrain, T. C., and H. A. Daubeny. 1986. Rel- 3. Feldmesser, J., D. I. Edwards, J. M. Epps, C. M. ative resistance of red raspberry and related geno- Heald, W. R. Jenkins, H. J. Jensen, B. Lear, C. W. types to the root lesion nematode. HortScience 21: McBeth, E. L. Nigh, and V. G. Perry. 1971. Esti- 1435-1437. mated crop losses due to plant-parasitic nematodes in the United States. Society of Nematologists, Com- mittee on Crop Losses, Special Publication No. 1.